Supervisory system



Patented Feb. 27, 1934 SUPERVISORY SYSTEM Hans Paul Boswau, Galion, Ohio, assignor to The North Electric Manufacturing Company, Galion, Ohio, a corporation of Ohio Application August 30, 1929. Serial No. 389,390

8 Claims.

My invention pertains to supervisory and signalling systems and, more particularly, to systems of this type which are designed for the purpose of indicating the positionof distant circuitsbreakers, or other apparatus units, to a centrally located dispatcher or system operator. It is to be understood, however, that my invention as disclosed herein has other applications and is not to be limited to the indication of circuit-breaker positions.

The principal object of my invention is to provide a simplified system of supervisory signals which shall require no latching relays, or other auxiliary equipment of this type, which is characteristio of signalling system of this class known heretofore. 4

Another object of my invention is to utilize the so-called glow-discharge lamp for signalling purposes instead of the incandescent-filament 2 type of lamp which has been used exclusively in the past. a

Secondary objects of my invention are to provide signalling systems which shall require less current for their operation and generate less heat while in operation.

In the majority of supervisory signalling systems suggested in the past, use is made of small incandescent lamps covered with colored lenses to provide an indication of the position of dis- 30 tant apparatus units, such as circuit breakers. It has been customary to control the circuits of these lamps by means of latching relays so that, when an indication has been established, it will be maintained until a reverse operation of the unit in question occurs. In accordance with my invention, I propose to utilize glow-discharge lamps and to eliminate all auxiliary equipment, such as latchingrelays, with the exception of two non-latching interlocking relays e ployed 0 in one modification of my invention to confusion of signalling indications.

The operation of the system of my invention, which will be described in detail: hereinafter, depends on the well known principle that a glowdischarge lamp, when once started, will operate on a voltage lower than that required for. the initiation of its operation, and that, when once started, such lamp will continue to operate until the voltage applied thereto is reduced considerably below its normal optimum operating voltage. V a

In order to make use of these principles, I provide a pair of glow-discharge lamps for indicating the two alternate positions of the circuit breaker or other movable element, and these revent lamps are normally connected to a source of current having a voltage such that the lamps will remain inoperative until a predetermined additional starting voltage is applied thereacross, after which the lamps will continue to operate on the voltage of the source connected thereto until the voltage thereof is decreased below the normal operating value.

For a complete description of my invention, reference is made to the accompanying drawing, in which Figure 1 illustrates a simple embodiment of my invention designed to indicate the position of an apparatus unit, such as a circuit breaker, which normally occupies one of two extreme positions, and

Fig. 2 is a diagrammatic illustration of a modification of my invention designed to afford an indication of the position of a unit which normally occupies a neutral or central position and,

occasionally, takes up an end position for a short time.

Referring to Fig. 1, the system of my invention comprises a movable element, (not shown) which may be any device, the operation of which it is desired to observe at a distance. Signalling lamps 10 and 11 of the glow-discharge type are provided at the observers station to indicate the position taken by the distant apparatus unit. The lamps 10 and 11 are connected across a current source, such as the battery 12, in series with portions 13 and 14 of the secondary winding of a transformer 15, which preferably takes the form of a telephone induction coil with a split secondary winding.

The primary winding 16 of the induction coil or transformer 15 is adapted to be connected alternately across current sources, such as the batteries 17 and 18, of diiferent polarities, by means of an auxiliary switch 19 which is so related to the apparatus to be supervised as to be actuated thereby.

I have illustrated the circuit to the primary winding 16 of the transformer 15 as including the contacts 20 and 21 which are normally closed during supervisory operation, and which are representative of the selecting-relay contacts in a standard type of supervisory control system such as'is disclosed in Patent 1,714,974, issued to White and assigned to the Westinghouse Electric and Manufacturing Company. It will be understood that the apparatus unit under observation and the signalling device may be a considerable distance apart, and, for this reason, it is desired to provide means for transferring a single cir-- no cuit or a small number of circuits successively from one apparatus unit and its associated signalling device to other sets of similar equipment, in order to reduce the initial cost of the signalling circuit. The means by which this transfer is accomplished is not a part of the present invention, but is well known to those skilled in the art. In explaining the operation of my invention, it will be assumed that the lamp 10 is operating to indicate the position of the distant apparatus unit corresponding to the lower position of the auxiliary switch 19, in which position the battery 17 is connected to the primary winding 16 of the transformer 15. At this point, it may be pointed out that the apparatus unit supervised may be automatic or it may be manually operated by an attendant or, as will usually be the case, remotely by well known supervisory-control systems.

When the apparatus unit changes its position for any reason, the auxiliary switch 19 will be of the flux in the core of the induction coil 15 will, obviously, cause a voltage impulse to be generated in the secondary windings l3 and 14 of the induction coil.

Connections are so made that, when the auxiliary switch 19 moves from its lower position to its upper position, the voltage impulse induced in the winding 13 will be in opposition to the voltage of the battery 12, which normally supplies current to the lamp 10, and, at the same time, the

impulse induced in the winding 14 will be in thesame direction as the voltage of the battery 12. The result of this design oi the circuits will'be that an increased voltage will be supplied to the lamp 11, whereas the voltage supplied to the lamp 10 will be decreased for an instant. It will be apparent that the lamps 10 and 11, and the induction coil 16 may be so designed that the changes in the voltage across the lamps 10 and 11 resulting from a reversal of the current in the primary winding 16 of the transformer 15 will be suificient to initiate the operation of the lamp 11 and to discontinue the operation of the lamp 10. In this manner, the indication of the signal lamps 10 and 11 is changed to apprise the observer of a change in the position of the distant unit.

The reverse of the procedure described above will be understood without further discussion. When the auxiliary switch 19 returns to its normal position, a voltage impulse will be induced in the windings 13 and 14, the impulse induced in the winding 13 being in the same direction as the voltage of the battery 12, while that in duced in the winding 14 opposes that of the battery 12. In accordance with the foregoing description, these impulses extinguish the lamp 11 and energize the lamp 10 to indicate that the unit has returned to its original position.

In Fig. 2, I have illustrated a modification of the system shown in Fig. 1, which may be adapted to slightly difierent uses. The glow-discharge .ferentiates Fig. 2 from that of Fig. 1 is the use of interlockingrelays 22 and 23 and their respective contacts 24 and 25 connected in series with the glow-discharge lamps 11 and 10.

The purpose of the interlocking relays is to prevent false operation of the signalling lamps upon a disconnection of the sub-station battery from the signalling circuit as a result of a movement of the switch 19 away from either of its associated fixed contacts without engaging the other set. Referring, for a moment again, to Fig. 1, it will be observed that if the auxiliary switch 19 moves away from its lower contacts without engaging its upper contacts, the deenergization of the winding 16 of the transformer 15 will induce a voltage impulse in the winding 13 and 14, as described above, but the magnitude of the impulse will, of course, be less than that resulting from an immediate reenergization of the winding 16 in the reverse direction. It is possible, of course, to utilize this characteristic and depend solely upon the voltage impulse resulting from the energization or deenergization of the winding 16. I am, therefore, able to dispense with one set of contacts and one battery at the sub-station, relying upon the change of flux in the core of the induction coil from zero to a predetermined value in one direction only, to produce the necessary impulse for initiating and discontinuing the operation of glow-discharge lamps 10 and 11.

It may be desirable, of course, in some cases to cause the lamp 10 to be extinguished as the switch 19 starts to move and to prevent the illumination of lamp 11 until the movement is actually completed. The system of Fig. 2 provides for this feature. Let it be assumed, for example, that the lamp 10 is in operation. Since the circuit of lamp 10 includes the winding of relay 22, the moving contact 24 of the relay will be withdrawn from engagement with its fixed contact, so that the circuit of the lamp 11 is maintained open. Now if the distant unit changes its position to open the circuit of the primary winding 16 at the lower contacts of switch 19, a voltage impulse will be induced in the windings 13 and 14 by the consequent collapseof the flux in the core of the induction coil 15. This impulse induced in thecoil 14 tends to energize the lamp 11 and the relay 23 in series therewith, as explained previously. The circuit of the lamp 11 being open at the contact 24, no such result is obtained and both lamps remain deenergized, the lamp 10 being deenergized by reason of the voltage impulse induced in the winding 13 in opposition to the voltage of battery 12. The deenergization of the lamp 10, of course, deenergizes the relay 22 and the-moving contact 24 engages its fixed contact.

When the movement of the auxiliary switch 19 v is completed and it engages the upper contacts to establish a circuit for the winding 16, through the battery 18 which has a polarity the reverse of that of the battery 17, the resulting voltage impulse induced in the winding 14 traverses the circuit including the contact 24, relay 2 3 and the lamp 11 to initiate the operation of the lamp. At the same time, an impulse opposing the voltage of the battery 12 traverses the circuit including the lamp 10, the relay 22 being deenergized and contact 24 closed, but no result is produced thereby since the lamp 10 was previously rendered inoperative.

From the foregoing description, it will appear that the two circuits shown and described differ in that that of Fig. 2 includes means for preventing the signalling devices from indicating the completion of a change until such change has actually been completed, whereas the system of Fig. 1 may tend to indicate the completion of the change before the change is actually effected, by reason of the fact that the interruption of the circuit of the primary winding of the induction coil 15 has an effect similar to that produced by the re-energlzation thereof by currents of reverse polarity, so that it may be difiicult to design the circuits and apparatus included therein to distinguish between an initial movement of a unit and the completion of its operation. The system of Fig. 2, in other words, represents merely an added refinement over that of Fig. 1.- The fundamental principles underlying the two, of course, are identical. I

hghe foregoing description will serve to em- D size that my invention is characterized by extreme simplicity and the utmost reliability. It is well known that the energy required for the operation of glow-discharge devices is small compared to that consumed by incandescent lamps of equal effectiveness for signalling purposes. As far as I am aware, it has not been proposed previously to make use of this type of lamp for'supervisory signalling purposes. In addition, the heat generated incident to the operation of the glow-discharge device is much less than that accompanying the operation of the incandescent lamp. Although the amount of heat generated by a single supervisory lamp of the incandescent type may not be large, when thousands of these lamps are mounted on a single panel it will be understood that the total amount of heat liberated will be sufficient to cause annoyance to operators in warm weather. For this reason, the glow discharge lamps will be of additional benefit.

Numerous other advantages of the invention described hereinbefore will, no doubt, be apparent to those skilled in the art.

Although I have shown and described only two modifications of the system of my invention, it is evident that numerous details thereof may be altered to suit any particular supervisory signalling system that may well be utilized in connection with devices other than circuit breakers. In fact, the operation of almost any movable device may be indicated by this system, which, as is apparent from the description thereof, is very simple and devoid of complicated circuits and apparatusa Since alterations may be made in the system without changing the scope of my invention, it is not to be limited to the precise details herein shown and described, except as indicated by the terms of the appended claims.

I claim as my invention:

1. A signalling system for a movable member having a plurality of operating positions comprising a plurality of ionic-discharge devices individual to the positions of said member, a source of current for said devices having a voltage between the minimum starting and operating voltages of said devices, means for momentarily decreasing the voltage applied to one of said devices and increasing the voltage applied to another to cause the latter to glow' comprising a transformer having a portion of its secondary winding in series with each of said devices, a.

switch controlled by said movable member for a source of current for said devices having 9. volt-- age insufiicient to initiate but adequate to maintain the operation of said devices and means including a second current source controlled by the movement of said member from one operating position to another for temporarily increasing the voltage applied to one of said devices and decreasing that applied to another whereby one of the devices begins and another ceases to operate.

3. A system of signalling for a movable element including ionic-discharge indicating devices, means for normally applying a voltage to said devices between the minimum starting and operating voltages of said devices, and means controlled by the movement of said element for momentarily increasing the voltage applied to one device and decreasing that applied to another device whereby operation of said first one of said devices is initiated and operation of said second of said devices is discontinued to indicate the change in the position ofthe movable element.

4. A system for indicating the position of a movable member having a plurality of operating positions comprising a separate glow-discharge 1 5. A system for indicating the position of a movable member having a plurality of operating positions comprising a separate glow-discharge lamp for indicating each position of the movable member, a source of current for said lamps, the voltage of said source being normally of such value as to maintain the lamps in a lighted condition but of insuiiicient value to cause either to initially light, and means dependent upon the movement of the movable member from one operating position to another for simultaneously superimposing an additional voltage on the source of normal operating voltage to increase the voltage applied to one lamp and decrease that applied to another, thereby to selectively energize and deenergize the lamps in accordance with the changes in operating position of the movable member.

6. The combination with a movable member having different operating positions, of means for automatically indicating changes in position of the movable member comprising a plurality of glow-discharge lamps, a battery for energizing said lamps, the voltage of the battery being only lamps from the first battery in a differential manner, thereby to selectively initiate the operation of the lamps, and switch means for-controlling the connection of the second battery to the last named means.

'7. An indicating system comprising a device operable to two positions, glow-discharge lamps for indicating the position of said device, a source 8. An indicating system comprising a movable,

device having a plurality of operating positions, glow-discharge lamps for indicating the 'movement of said device from one position to another, a source'ot current for said lamps having a voltage between the minimum starting and operating voltage of said lamps, and means for momentarily increasing and decreasing the voltage applied to said lamps including a transformer having a portion oi. its secondary winding connected in series with each of said lamps, a second source of current, and circuit means actuated in accordance with the movement of said device from one or its positions to another for reversing the polarity of the voltage or the second current source asapplied to the primary winding of the transformer whereby, when said device moves from one position to another, one or the lamps is illuminated and the other extinguished.

HANS PAUL BOSWAU. 

